Control: retitle -1 Kernel Oops when using parport_serial and specifying console=ttyS0
On Thu, 2014-11-13 at 15:59 -0800, Nikolaus Rath wrote: > Control: tag -1 -moreinfo > > On 11/13/2014 01:45 PM, Ben Hutchings wrote: > > On Thu, 2014-11-13 at 12:53 -0800, Nikolaus Rath wrote: > >> Package: src:linux > >> Version: 3.16.7-2 > >> Severity: normal > >> File: /boot/vmlinuz-3.16.0-4-amd64 > >> > >> Hello, > >> > >> When adding > >> > >> console=ttyS0,115200n8 console=tty0 no_console_suspend > >> > >> to the kernel command line, I'm getting the following kernel Oops during > >> boot (full quote in kernel.log below): > >> > >> [...] > >> [ 13.687971] 0000:07:01.0: ttyS0 at I/O 0xc050 (irq = 19, base_baud = > >> 115200) is a 16550A > >> [ 13.687980] kernel tried to execute NX-protected page - exploit > >> attempt? (uid: 0) > >> [ 13.688130] BUG: unable to handle kernel paging request at > >> ffffffff819419bf > >> [ 13.688299] IP: [<ffffffff819419bf>] serial8250_console_setup+0x0/0xaa > >> [ 13.688604] PGD 1816067 PUD 1817063 PMD 215f93063 PTE 8000000001941163 > >> [ 13.688911] Oops: 0011 [#1] SMP > >> [...] > >> > >> Please let me know if I can do something to debug this further. > > [...] > > > > The log didn't include the full oops message; please can you send that > > as I don't understand why anything would call this function at this > > point. (It is only meant to be called during kernel initialisation, > > before starting the init program. At this point the code has been > > freed, hence the page fault.) > > Full log is attached. Sorry, I did not realize that the automatically > included log was truncated. This bug seems to be specific to parport_serial. Only built-in drivers can be console drivers, but parport_serial is built as a module. However, because it works on top of with 8250_pci, which *is* built-in, the kernel tries to use it as a console driver anyway, and this leads to the crash. We should fix the crash, but you still won't be able to use ports on the combined parallel/serial card for a console. Ben. -- Ben Hutchings Never put off till tomorrow what you can avoid all together.
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